1. Field of the Invention
The present invention relates to a power antenna apparatus, and more particularly, relates to a power antenna apparatus which, in a mobile communication apparatus such as a cellular phone and the like, enables an antenna to be automatically drawn out or led in.
2. Description of the Prior Art
Generally, a power antenna apparatus pulls an antenna into an antenna housing when not in use, draws out the antenna from the antenna housing by a rotational force of an electric motor when in use, and leads to pull the antenna again into the antenna housing when the use of the antenna is completed.
Recent researches into and developments on the technology of power antennas have been applied to antennas for mobile communication apparatuses such as mobile telephones, cellular phones and a personal communication system.
There has been a technology in which the drawing-out or the lead-in of an antenna is controlled by installing a rod at a lower end portion of the antenna and by transporting a screw rod with a turning force of an electric motor. Here, because the screw rod needs to be transported, a length of an antenna housing is required to be twice as long as a drawing-out length of the antenna. Also, because an external force which has an influence on the antenna is delivered to a transport mechanism as it stands, the external force acts on the transport mechanism or on the electric motor and thereby they are apt to be damaged or broken down.
In U.S. Pat. No. 5,497,506, disclosed is a technology in which the drawing-out or the lead-in of an antenna is activated by installing a transport nut at a lower end portion of the antenna and by transporting the transport nut under the guidance of a spiral of a screw rod with a turning force of the screw rod which is rotated by an electric motor. In this patent, because the screw rod is received into an inner side of a pipe-shaped antenna, a length of an antenna housing is required to be the same as a drawing-out length of the antenna. Similarly, because an external force which has an influence on the antenna is delivered to a transport mechanism as it stands, the external force acts on the transport mechanism or on the electric motor and thereby they are apt to be damaged or broken down.
Therefore, it is an object of the present invention to provide a power antenna apparatus in which, while an antenna transport assembly transports under guidance of a spiral of a rotating coil spring, a drawing-out or a lead-in of an antenna is controlled, an external force acted on the antenna is absorbed at the same time, and thereby the durability of a driving apparatus can be improved.
It is another object of the present invention to provide a power antenna apparatus in which an external force is absorbed by a coil spring and thereby a motor control circuit is configured by a simplified on/off control.
It is a further object of the present invention to provide a wireless communication apparatus which adopts the power antenna.
It is a fourth object of the present invention of the present invention to provide a power antenna apparatus which a motor as a power source for driving the antenna can allow to installed in a random place so that its application field can be extended to a mobile telephone with a narrow permissible space for installation.
According to the present invention, there is provided a power antenna apparatus for extracting/retracting an antenna from/into an antenna housing, comprising; a driving means for generating a rotational force; and a transporting means, accommodated in the antenna housing, for carrying the antenna in a longitudinal direction of the antenna as being conveyed along a spiral of a coil spring which is rotated by the driving means.
As another preferable aspect of the present invention, there is provided a power antenna apparatus for automatically extracting/retracting an antenna of a wireless communication device, comprising; a motor for generating a rotational force by using an electric energy; a motor control means for controlling operation of the motor by providing a driving power in response to a communication-start signal and a communication-end signal of the wireless communication device; an antenna housing having a guide slot extending longitudinally on an inner surface of the antenna housing; a rotary member installed at one end of the antenna housing and rotated by the motor; a coil spring rotatably accommodated in the antenna housing, one end of the coil spring being fixed to the rotary member; and an antenna conveying member received together with the antenna within the coil spring as being fixedly coupled with the antenna by a lower end of the antenna, having protrusions which are loosely inserted into the guide slot of the antenna housing, for conveying the antenna along with the guide slot to extract or retract the antenna by means of rotation of the coil spring.
As a further preferable aspect of the present invention, there is provided a power antenna apparatus for automatically extracting/retracting an antenna in a longitudinal direction of the antenna, comprising; a motor, having a driving shaft, for generating a rotational force by using an electric energy; a deceleration gear assembly engaged with the driving shaft of the motor; an antenna housing having a guide slot extending longitudinally on an inner surface of the antenna housing; a rotary member rotatably accommodated in the antenna housing and rotated by a transferred rotational force originated from the motor; a force transferring means, both ends thereof being fixed to the deceleration gear assembly and the rotary member, for transferring the rotational force of the motor to the rotary member; a coil spring rotatably accommodated in the antenna housing, one end of the coil spring being fixed to the rotary member, rotated together with the rotary member; and an antenna carrying member received together with the antenna in the coil spring as being fixedly coupled with the antenna by a lower end of the antenna, having protrusions which are loosely with the guide slot of the antenna housing, for carrying the antenna along with the guide slot to extract or retract the antenna by means of rotation of the coil spring.
As an preferable aspect of an application of the power antenna apparatus to a wireless communication apparatus, for example, a cellular phone and the like, there is provided a wireless communication apparatus having an antenna which is moved in a length direction thereof so as to be extracted from or retracted into a case of the wireless communication apparatus, the wireless communication apparatus comprising; a means for inputting/outputting an information; a transmitting/receiving circuit means for processing an input/output signal from the inputting/outputting means, for modulating the processed input/output signal into a radio signal and then transmitting the modulated radio signal through the antenna, or for demodulating a signal received through the antenna, processing the demodulated signal and providing the processed signal to the inputting/outputting means; a driving means for generating a rotational force in response to an operation of the transmitting/receiving circuit means; and a means for carrying the antenna, tightly coupled with the antenna, the carrying means moving in a longitudinal direction of the antenna along a spiral of a coil spring when the coil spring is rotated by the rotational force of the driving means, thereby carrying the antenna in the longitudinal direction.